Generally in liquid crystal displays, an alignment of liquid crystal molecules located between pixel electrodes and a counter electrode is changed by applying an electric field between the pixel electrodes and the counter electrode. A light transmittance is controlled in accordance with a change in the alignment of the liquid crystal molecules, and images are formed in accordance with the controlled light transmittance. Of the various types of liquid crystal displays, an Optically Compensated Bend (OCB) mode liquid crystal display is known to have a fast response speed and an excellent viewing angle. An OCB mode liquid crystal display includes pixel electrodes, a lower alignment film, a counter electrode, an upper alignment film, and a liquid crystal layer including nematic liquid crystal molecules having a positive dielectric constant anisotropy (Δε). The lower alignment film and the upper alignment film are rubbed (and/or coated) in the same direction, and thus the liquid crystal molecules have a splay alignment.
In order to allow the OCB mode liquid crystal display to form an image, a high electric field is first formed between the pixel electrodes and the counter electrode. The high electric field changes the tilt angle of the liquid crystal molecules positioned at the center of the liquid crystal layer to be an angle of 90°, and thus the liquid crystal molecules have a bend alignment. This is referred to as a bend transition. Subsequently, a predetermined voltage is applied between the pixel electrodes and the counter electrode, thereby causing the change in tilt angles of the liquid crystal molecules other than the liquid crystal molecules adjacent to the alignment films and the liquid crystal molecules positioned at the center. As a result, a polarized light passing through the liquid crystal layer is modulated to form an image.
When a liquid crystal display includes a plurality of pixels, most of the liquid crystal molecules disposed in the plurality of pixels should be transited to bend alignment. However, a bend transition of most liquid crystal molecules requires a considerable period of time, and pixels having liquid crystal molecules not being transited to bend alignment may still exist. In order to solve this problem, the predetermined voltage applied for the purpose of the bend transition may be increased, but this can cause increase in power consumption.